In Australian Patent Application No. AU-A-78219/87 there is described a unit which will controllably release the gas from a pressurized bulb or the like, this release of pressure being controlled during the dispensing of the product from a can in which the unit is positioned.
Also there is known U.S. Pat. No. 4,456,155 for an aerosol spray device in which a gas bulb is positioned in the container, this being sealingly mounted within the container by being attached to an aperture in the bottom of the container, so that means can be available to hold the gas regulating position in an inoperative condition until the unit is inserted and the container sealed.
Japanese Patent No. 62066873 discloses a fire extinguisher which uses a gas bomb containing a mixture of nitrogen gas and carbon dioxide gas.
It is an object of this invention to provide a unit with the least number of parts and also it is a still further object to provide a unit which has the provision of a fail safe property, and is also self-regulating.